Process for separating the hydroxy-acids from the oxidation products of hydrocarbons



- Patented Nov. 1, 1932' 7 UNITED STATES PATENT OFFICE THEODOR HELLTHALER, or enansontm'z, AND Enron PETER, or WEBAU, GERMANY, ASSIGNORS TO rmm A. nrnnncx'scnn MONTANWERKE nxrrnnensmmscmr, or

HALLE, GERMANY PROCESS FOR SEPARATING- THE HYDBOX-Y-ACIDS FROM 'OF HYDRQCARBONS 1% Drawing. Application filed April 28, 1930, Serial No. 446,780, and in GermanyAprfl 10, 1928.

This invention relates to a process for separating the hydroxy-acids from the oxidation products of hydrocarbons, especially paraflin, or waxes and similar substances.-

5 I By oxidizing paraffin and other hydrocarbons, waxes or similar substances with oxygen or oxygen-containing gases, mixtures are obtained which contain hydroxy-acids besides unsaponifiable portions, normal fatty acids and their esters. Of course, the percentage of such hydroxy-acids depends upon the 0x1dation method employe As a-rule, the percentage of oxidized acids increases the further the oxidation proceeds. F or instance,

applicants found in a paraflin, oxidized to a far-reaching degree, about 30% of hydroxyacids. I

Hitherto themain object of oxidizing hydrocarbons and similar substances was to obtain fatty acids from which soaps and the like could be produced. Hyrdoxy-acids, however, are not suitable for making grained soap and for distilling fatty acids.

Now we have ascertained, that from the v raw mixture of variousproducts obtained by treating with oxidizing gases paraflin or other hydrocarbons, waxes and similar substances, before or after the separation of the unsaponifiable matter, the hydroxy-acids may be separated, to a. far-reaching extent and in a simple and economic manner, by heatingthe mixture withlow-boiling hydrocarbons (boiling point lower than 125 0.), especially petroleum ether (boiling point lower than 60 0.), settling and decanting, or separating in any other way, the solution from the undissolved residue. Hereby, on the one'hand, the hyrdoxy-acidsare enriched to a considerable extent in the insoluble portion and, on the 40 other hand, the portion, which is soluble in light benzine or petroleum' ether, is freed "from the main part of the oxidized acids, and therefore is considerably more useful for crtain purposes, for instance, for making grainedsoap 1 than the starting material.

Moreover, the color of greatly cleared.

the refined product is lVe are aware thatit has been proposed to I I separate the oxidation products of hydrocarbons into solid and liquid fatty acids by treating them with petroleum or similar hydrocarbons. From this process our invention difi'ers in that we employ solvents, such as petroleum ether or low-boiling benzines, which dissolve fatty acids by far easier than hydroxy-acidsflv Therefore according to our process substantially the fatty acids (excluding the hydroxy-acidsl are dissolved whereas thehydroxy-acids and the unsaponifiableconstituents, which "may still be present in the to a large exten It is a surprising fact that bya simpletreatment with petroleumether the hydroxy-acids can be precipitated in a high concentration from the mixture of oxidation products of hydrocarbons, waxes and similar substances. By oxidizing these materials various suboxidized hydrocarbons, remain undissolved stances are formed which are all good solvents for hydroxy-acids. Therefore it was to be feared that these bodies would largely act as mediators of dissolution in the' presence of ordinary pressure or, for accelerating the dissolution, under a moderate pressure over atmospheric; in the latter case the hydroxy acids are obtained in a highly concentrated state. 7 1

The hydroXy-acids 'obtained according to the present-invention are distinguished from the commercial hydroxy-acids, hitherto on the market, by their higher percentage of pure hydroxy-acids and by a lighter color.

For instance, from the raw product resulting from oxidizing paraflin at 17 0 0., by means of a strong current of air in presence of cata-' lysts, light-yellow or even nearly colorless hydroxy-acids were obtained.

Therefore by our new process not only the value of the oxidized hydrocarbons, waxes, and similar substances for certain purposes, for instance, in the manufacture of soap, is increased, but also hydroxy-acids are obtained which are superior heretofore obtained from other raw materials emulsions of various types,

- of hot petroleum ether 1. 100 grams of an oxidized paraflin obtained by treating paraffin with air at 180 C. were refluxed with petroleumether (boiling between 30 and 50 C.) The resulting solution was decanted when hot from the molten undissolved residue, and the ether was removed from the residue and the extract by distillation. 42 grams of the residue and 58 grams of the. extract were obtained. The properties of the raw material and the separated products were do s l g p a a O E a Fl 9 .O z m n '0 5 g g :1 o g H a I o O a *3 as s '3 a a e 0 Ft F11 m 1 1 Raw material- Dark-brown-.. s9 84 141 225 20 lnsptlluble in petrol Dark-brown- 18 109 165 274 35 6 81'. Petrol ether ex- Light-brown" 39 63 106 169 12 The hydroxyacids were tested after the Fahrion method (saponifying the products with ethyl-alcoholic caustic soda solution containing 80 grams NaOI-I per liter, evaporating the alcohol, dissolving the residue in little water, decomposing the soaps by hydrochloric acid, extracting the mixture with petroleum ether, removing the separated hydroxy acids, dissolving them in ethyl alcohol and evaporating the latter).

2. 300 grams of a product obtained by intensely treating paraflin with air in the presence of catalysts were shaken with 900 grams for 15 minutes; then the solution was decanted when hot from the molten residue. By. evaporating the ether 190 grams of an extract (1) were obtained.

The undissolved residue, 110 grams, wasto any hydroxy-acids anew treated in the same way with 300 grams of petroleum ether. Further 20 grams of an extract (11) and 90 grams of a residue insoluble in petroleum ether were obtained.

The properties of the raw material andthe separated products were as follows Fusiop Sa:

om pom Acld- Ester- Hy- Color ag numnumdroxycenti ber her be: acids grade Raw material Lilght yel- 40 80 104 184 20 ow. Insoluble in pe- Pale yellow- 18 117 167 284 41 trol ether. Petrol ether ex- Pale yellow. 41 83 153 10 tract I. Petrol ether ex- Pale yellow- '37 67 86 153 10 tract II. v

3. A wax fraction obtained by distilling Montan wax in a current of steam and showing a fusion-point of 58 C. was transformed,

treating it with air at 175 into a yellow product showing Fusion-point 51 C. Acid-number 50 Saponification number 122 Contents of hydroxy-acids accordingto Fahrion 23% (a) 100 grams of this oxidation product were refluxed according for 30 minutes with 500 grams of a Pennsylvanian light benzine having a specific gravity of 0.686, highest boiling temperature 105 C. Two layers were separated from each other, the upper one containing almost the whole solvent, whereas the lower one had absorbed only a slight amount of the solvent. The solvent was evaporatedfrom both layers. In this way, products were obtamed showing the following propert1es:-

From From thelower theupper layer layer Color Brown- Yellow yellow. Acid-number 71 48 Saponiflcation number 176 118 HYgIOlY-acld contents according to Fahrion 50% 15.8% a on matter soluble in light benof that insoluble in light The determination of the hydroxy-acids in the matter insoluble in benzine is believed to have furnished too high a value in this case, as the hydroxy-acids may have contained a certain amount of high- The output of zine was 91.4%, benzine 8.6%.

C. for 5 hours,"

to the present invention formed which were fusing-fatty acids from the Montan wax dis- I tillate.

(b) By 9. grams of the same oxidation product were separated, for removing the non-oxidized hydrocarbons, into 29 grams of a residue and 71 grams of a pasty waste. The latter only contained 20% of unsaponifiable matter,

moderate pressure at 35 C. 100

whereas the residue from the pressing operation contained 62% of unsaponifiable matter. This treatment may be repeated, if desired.

Now the waste from the pressing operation was subjected to the treatment described sub ((1) according to the present invention. We obtained, calculated upon the waste, 14.6% of matter insoluble in light benzine 85.4% of extract.

The matter insoluble in light benzine had a brownish-yellow color and a saponification number of 206, and contained 42% of hy-.

droxy-acids, determined after the Fahrion method. The extract from the light benzine contained 13% of hydroxy-acids with a saponification number of 203.

4. An oxidation product obtained by treating ceresine with air at 175 C. 'for 8 hours, showing a dark-yellow color and containing 22% of hydroxy-acids and 33% of unsaponifiable matter was extracted with an 85% alcohol to remove the hydrocarbons contained therein. 85.5% of the oxidation product were dissolved. After distilling oil the alcohol the extract still contained 22% of unsaponifiable matter, whereas in the residue, insoluble in alcohol, 60% unsaponifiable matter were determined substantially consisting of nonoxidized hydrocarbons.

The extract obtained by the alcohol treatment was separated into two portions by twice extracting it, each time with the threefold amount of light benzine of 0.686 specific gravity and uniting the extracts thus obtained.

The ortion soluble in light benzine showeda fusion-point of 39 C. and contained 12% of hydroxy-acids, whereas the matter insoluble in light benzine showed a fusion-point of 32 G. and contained 41% of hydroxy-acids.

When the ceresine oxidation product is treated with light benzine in the above-described manner, without, however, previously removing the'high-fusing hydrocarbons, the portion insoluble in light benzine and enriched with hydroxy-acids shows a fusionpoint of 83, the extract obtained by the light benzine treatment showing a fusion-.

point of 53.5 C.

We claim 1. In the process for separating the fatty acids and hydroxy-acids contained in the products obtained by oxidizing hydrocarbons, the steps which consist in heating the said oxidized products with low-boiling benzines which are bad solvents for the hydroxyacids, and separating the resulting solution from the undissolved matter.

2. In the process for separating the fatty acids and hydroxy-acids contained in the products obtained by oxidizing hydrocarbons, the steps which consist in heating the said oxidized products with petroleum ether, andseparating the resulting solution from the undissolved matter.

3. In the process for separating the fatty acids and hydroxy-acids contained in the roducts obtained by oxidizing hydrocarons, the steps which consist in removin the unsaponifiable matter from the said oxi ized products heating the residue with low-boiling benzines which are bad solvents for the hydroxy-acids, and separating the resulting solution from the undissolved matter.

4. In the process for separating the fatty acids and hydroxy-acids contained in the products obtained by oxidizing hydrocarbons, the steps which consist in removin the unsaponifiable matter from the said oxi ized products, heating the residue with petroleum ether, and separating the resulting solution from the undissolved matter. 7

5. In the process for separating the fatty acids and hydroxy-acids. contained in the rating the resulting solution from the undissolved matter.

7. In the process for separating the fatty acids and hydroxy-acids contained in the products obtained by oxidizing hydrocarbons, the steps which consist in removin the unsaponifiable matter from the said oxi ized products, heating the residue under superatmospheric pressure with low-boiling benzines which are bad solvents for the hydroxyacids, and separating the resulting solution from the undissolved matter.

8. In the process for separating the fatty acids and hydroxy-acids contained in the products obtained by oxidizing hydrocarons, the steps which consist in removing the unsaponifiable matter from the said oxidized products, heating the residue with petroleum ether under superatmospheric pressure, and

separating the resulting solut on from the undissolved matter.

.9. In the process for separating theffatty acids and hydroxy-acids contained in the products obtained by oxidizing hydrocarbons in the presence of a catalyst, the steps which consist in heating the said oxidized products with low-boiling benzines which are bad solvents for the hydroxy-acids, and separating the resulting solution from the undissolved matter. I

In testimony whereof we aflix our signatures.

THEODOR HELLTHALER. ERIOH PETER. 

